Description of Problem:
When eventually coerced to leave some space at the beginning of a disk
for a boot block Disk Druid raises a stink claiming that a minimum 5
Megabytes of a free space is needed. This is totally bogus. The
whole partition table sits on an initial disk sector, one more sector
is left blank and a boot block, which is around 80k, starts on the
next one. In other words around 100 KiB will leave some slack. In
practical terms keeping the first cylinder free is more than
ample. Depending on a disk geometry this likely will be between five
to ten times more than a required space.

Phil,
disk controller has nothing to do with it. In a situation when half
megabyte is a gross overestimate warnings about 5 Megabytes required are
just counterproductive. One cylinder reserve is just a convenient way
to partition things and as long as anaconda is unhappy with anything
above, say, 250K just to leave a _very_ ample margin then I can only repeat
that this is bogus and makes anaconda look clueless.
So, do you know an example of a real disk controller and a disk with a cylinder
below 100k? That would be pretty interesting with anything which realistically
can be used. I am all ears...